Flickering one one monitor
So I have a dual monitor set up. It flickers on my main monitor whenever I do something that causes movement. For example hovering over tiles for youtube videos I can select, switching tabs, selecting the address bar, etc. But on my secondary monitor this issue doesn't exist (and I've tried to replicate it). I have tried the same actions and websites on google chrome on my main monitor to see if I can recreate it and narrow it down to a monitor problem however I couldn't get the flickering to occur once on chrome on my main monitor. If I place firefox in a neutral position (split between both monitors) and create the flickering it only flickers on the main one. This happens when the window isn't taking up the whole screen as well.
My main monitor is 1440p, 165 hz, gysnc, my secondary is 1080p 60hz. Any idea what the issue is?